Controlling means for fluid-circulating apparatus



Feb. 20, 1923.

G. P. CARROLL.

CONTROLLING MEANS FOR FLUD CIRCULATING APPARATUS.

3 SHEETS SHEET l.

FILED JAN.V11.19IB.

wmN mwN wwmmmmmmm m72 fw Feb. 20, 1923. 1,445,752.

G. P. CARROLL.

CONTBOLLING MEANS FOR FLUID CIBCULATING APPARATUS.

FILED JAN-17, 1918. l 3 SHEETS-SHEET Z- NVENTOR.

(. P. CARROLL.

Feb. 20, 1923.

CORTROLLING MEANS FOR FLUID CIRCULATING APPARATUS.

3 SHEETS-SHEET 3- FILED 1AN.I7, 191B.

wl; A l

NVENTOR.

` appear.

Patented eb. 20, 1923.

FICE,

GEORGE P. CARROLL, OF HARTFORD, CONNECTICUT.

CONTROLLING MEANS FOR FLUID-CIRCULATING APPARATUS.

Application led January 17, 1918.

To all whom t may concern Be it known that I, GEORGE P. CARROLL, a citizen of the yUnited States, residing at Hartford, in the county of Hartford and State of Connecticut, have invented a new and useful Controlling'Means for Fluid-Circulating Apparatus, of which the following is a specification.

yMy invention relates especially, but not exclusively, to means for controlllng the operation of apparatus that circulates a fluid employed for refrigeratin purposes; and in part it relates to means or controlling the operation of all kinds of apparatus that draw in any vaporous or gaseous Huid at low pressure, compress it and force it into a condenser where the heat of compression is carried away, with or vwithout fa. resulting liquefaction of the flui termcondenser comprises allof the vessels leading from the discharge valve of the compressor or other compressing means and containing fthe .fluid under high pressure, whether in` a liquefied or in a non-liquefied state. F orconvenience, a. very simple form of condenser is herein shown.

The purpose of myinvention in part is to provide simple, compact and reliable means whereby predetermined temperatures may be maintained in a plurality Aof compartments, in part is to economize the operating power of the liuidcirculating means, in part is to regulate the capacity of certain' fluid circulatmg means according to head pressure conditions, in part is to secure such regulation l for refrigerant liud circulating means according to temperature requirements, in part is to provide simple and economical means vfor regulating the flow of condenser .cooling water and in part is to provide simple, safe and eliicient elements of construction for all such `l'luid circulating apparatus. The means for accomplishing these purposes Certain detail improvements of construction will also so My invention will be particularly disclosed in connection with a machine circulating ammonia as a refrigerant, this being a construction typical of all.

In the drawings, Fig. 1 is a diagram matic representation `of one form of my in-` -vent1on.

Fig. 2 is a plan view of the right endof the lever 36 shown -in Figs. 1 and 4 and of the lever 36x1 shown in Fig. 3, and of their respective connections, broken` away.

Fig. 3 in part is a representation, partially As herein used, the

xerant pipe 5 leads to the left.

.- to discharge into theof 250 pounds and Serial No. 212,263.

in front elevation and partially in Vertical section, of part of the structure of Fig. 1 and in part is an alternative construction for a portion of that structure. Fig. 4 is a, partial front elevation and a partial vertical section of part of the structure of Fig. 1. Fig. 5 is a front elevation of part of the master re. frigerator thermostat shown ig. 6. is a partial front elevation anda partial vertical section of a subordinate refrigerator thermostat shown in Fig. l, with its connections. Fig. 7 is a diagrammatic representation of the windings and wire connectionsl of an electric motor adapted for use in connection with the structureof Fig. 3. Fig. 8 is a diagrammatic representation of certain wire connections that may be-used, by way of alternative construction, in place of certain other wire connections shown in Fig. 3. Fig. 9 is a front elevation of a'reservoir and float device that may be used, by way of alternative construction, in place of a certain other construction shown in Figs. 1 and 3. Fig..l0 representsa transposition of certain parts shown in F ig. 1. First considering Figs. 1, 2, 4 and 6 and a part of Fig. 3: A condenser tank 1,pro' vided on top with a gage 2, has water piping 3, leading downward from a point above the tank'into the lower part of the tank, coiling upward therein, emerging from its upper part and discharging downwardly therefrom. A compressor discharge pipe 4 leads upward, thence to the right and thencedownward into the top of the tank 1. *From the under side of the tank 1 a li uid refrigpipe 6 of small diameter connects ther top of the tank l with the lower endof a shallow casing 7, provided, as shown in Figs. 3 and 4, with diaphragm stops 8 and enclosed on top by a. diaphragm 9, preferably of -very thin vanadium steel. The parts 1-9 represent a condenser, including water piping therefor, which may be a condenser, an atmospheric ,condenser or any other kind Iof condenser, An automatic safety orr relief valve 10 is connected with the-highest part ofthe pipe 4 and is adapted atmosphere; Forv ammonia, the discharge limit may be 300 pounds; but the best considered safety regulations in cooler latitudes are now requiring such a valve. to begin to open at a pressure to be f lly open at a pressure of 275 pounds. 'l

in .Figa f3.

double pipe counter current- A pipe 11 leads into the lower left side of a reservoir casing 12. From the lower right side of the casing 12 a smaller horiprotected against corrosion; and, if constructed of any such material, of a suitable A thinness, it is sensitive to pressure changes vso as to permit the head to move up or down along the line of the axis. The parts 11-16 constitute one form of water reservoir draining into the piping 3 and may be of any necessary or proper capacity. l

-A clapper valve 17, adapted to close the seat 15, is secured at the top within the casing 14 to the front end of a shaft 18 that extends through the back wall of the casing. Secured to the rear and outside end of the shaft 18 is a short lever 19, extending horizontally to the right. A light compression spring 20 at its lower end bears v@upon a bracket projecting to the right from the casing 14 and at the top bears upward against the under side of the outer end of the lever 19. A headed bolt 21 is adapted to be screwed up or down in a threaded vertical opening through the lever 19 and is secured in any desired position by a locknut 22, just .above the lever. The tendency of the spring 2O is to press upward upon the lever 19 so as fully to open. the valve 17. When the valve 17 is fully open, there is a maximum flow of water permissible through the casing 14. But, u` on a pressing down of the bolt 21, the va ve 17 begins to close, and, if fully closed, it prevents any How through the casing 14.

'llhe diaphragm 9 near its circumference rests upon a ring at the top of the casing 7 and atpits circumference rests upon an anlying o n the downwardly sloping rim of the casing just outside the ring. The stops 8 are intended to prevent an excessive downward movement of the diaphragm 9. lt is to be understood that in Fig. 3 the lowest position of the diaphragm 9, when the parts are assembled, by reason of the positioning of the stationary parts, is a little above the stops 8, as shown; and that in lFigs. 1 and 4 the lowest position of the diaphragm is upon the stops, as shown in the latter fig-ure. There are passages between the stops '8 so that fluid under pressure may be transmitted back and forth between the space under the diaphragm 9 outside of the stops and the .nular gasket 23, preferably of soft lead,

mames pipe 6. An' upper casing 24 has a flange that fits over so much of the diaphragm 9 as rests upon the casing 7 and the gasket 23 and it has at its extreme circumference an annular tongue enclosing the outer vertical surfaces of the diaphragm andthe gasket. By means of bolts the casings 7 and 24 are clamped together at their circumferences and press the edge of the diaphragm 9 and the gasket 23 between the casings. The casing 24 has in its under side a shallow chamber of equal diameter with the chamber in the top of the casing 7; it has at its axial center a cylindrical chamber extending upward from the shallow chamber nearly to the top; it has a small threaded passage'at its axial center extending through the top; and it has a space at the lower right side of the cylindrical chamber from which a horizontal shaft passage extends through the rear wall. A reciprocating member 26 has a flange at the lower end resting upon the center of the diaphragm 9 and of a diameter greater than that of the stops8; above its flange it is adapted to reciprocate within the lower end of the cylindrical chamber in the casing 24; and it has in the part so reciprocating a transverse passage extending from left to right. The upward movement ofthe member 26 would be limited, in case of an extremely high pressure on the under side of the diaphragm 9, by its flangestriking the wall of the casing 24 around the lower end of the cylindrical chamber therein. A heavy compression spring 27 occupies the upper end of the cylindrical chamber in the casing 24 and it bears, at the lower end, upon the top of the member 26 and, at the upper end, upon the head of a bolt 28 passing upward through the passage in the top of the casing 24. The end of the bolt 28 above and out- Side the casing 24 has a square wrench section whereby the bolt may be turned up or down and it is held in any desired position by a lock nut 29 just above the top of the casing. llt is evident that, upon loosenwhich is of reduced diameter, and over the nut 29 and the exposed end of the bolt 28. A wire 31 is passed through holes in two lugs projecting to the right from the cap 30 and the casing 24, respectively, and is sealed after the bolt 28 and the nut 29 have been adjusted as desired. A rock shaft 32 is journaled at its rear end in the front end of a support 33; it enters the rear wall'of the casing 24 through a stuffing box gland nut 34; `and it has secured to its 'front end within the casing a short lever 35 that has its free end within the recess of the member 26. ln Figs. 1 and 4 a long lever 36 is secured to y3 a long lever 36a is` secured to the shaft between the nut 34 and the support 33, at its outer end'it tends to bear upon the head Aof the bolt 21 and neai` its outer end 1t carries a transverse conductor 36h, insulated from 1 36a and 36b constitute another form of controller.

With the stationary parts positioned as shown in F ig. 3, in the absence of a countervailing pressure on the under side of the diaphragm 9the spring 27 bears downward upon the member 26 so that the parts 35, 32, 36, 361?, 21, 22, 19 and 18 are so turned th-at the valve 17 completely closes the seat and prevents anyfwater whatsoever from flowing through the casing 14. Then, after such complete closing, when the pressure on the under side of the diaphragm 9 exceeds the thrust of the spring 27 the lever 36 is lifted upward and the spring 20 forces the bolt 21 to follow the leven so thatl the Valve is gradually opened more and more and finally to its full limit, if the' lever i is lifted far enough. With the station-ary parts positioned as'shown in Fig. ,4, the

- positioning thereof in Fig. 1 being the same',

in the absence of a 'countervailing pressure on the `under side of the diaphragm 9, the sp-ring 27 bears downward upon the member 26 so that the parts 35, 32, 36, 21, 22, 19 and 18 are so turned that the valve 17 never entirely closes the seat 15 and thus -always permits an escape of water from the casing 14, thus resembling the construction disclosed in my aforesaid applications Ser. No. 126,019 and Ser. No. 146,147. Then, after such partial closing, when the pressure on the under side of the diaphragm 9 exceeds the thrust of the spring 27, the lever 36 is lifted upward and 46 the spring 20 forces the bolt 21 to follow the lever so that the valve is gradually opened yet more and more fullyand finally toits full limit, if the lever is lifted far enough. y Leading into the inlet end of t-he pipe 11 is an electrically operated means 37 for controlling a flow of cooling water to thereservoir composed of the parts 11-16, the inlet end of the means being connected to a source i of cooling water, not shown. The particular means indicated isthe electric valve disclosed in the patent issued to /lne on' the application of Roehrich, No. 959,609, dated May 31, 1910, having a construction such that upon ana instantaneous energization of a magnet winding 21x thereof the valve is opened to the full limit and upon an instantaneous energization of a magnet winding 40x thereof the valve closes. The capacity of the means 37 and of all passages leading thereto must be such, and the presthe main part of the lever. The parts Z4-35,

sure ofthe transmitted water must be, such, that, whenwater is flowing therethrough, the reservoir composed of the parts 11-16 will be completely filled and the bellows 16 will be lifted to its highest limit even although the valve 17 is wide open and the passages leading therefrom are transmitting the full flow of water permitted by the valve being so open.

Leading from the outlet end of thepipe 5 is an electrically operated feed valve 38, being the valve disclosed in said Patent No. 959,609, having a construction such th-at upon an instantaneous energization of a magnet winding 21y thereof the valve is S0 opened'to the full limit and upon an instantaneous energization of a magnet winding 40Y thereof the valve closes. A T 39 is connected with the outlet end of the valve 38 and from one outlet of the T 39 a feed pipe 85 40 leads through the wall` of a master compartment 41 and to an automatic expansion valve 42. The valve 42 and the similar valves 50 and 56, to be indicated, may be of the construction disclosed either in the patent to me No. 906,508, dated Dec. 15, 1908, or in the patent to m'e upon the application of Roehrich and myself, No.. 1,137,051, dated Apr. 27, 1915. Vithin the compartment 41 isV a master expansion chamber 43, also called an evaporator or expansion coil, leading from the valve 42, having its coils within the compartment and leading outward through the wall of the compartment to a T 44. A T 45 is connected with the other outlet ofthe T 39 and from one outlet of the T 45 a feed pipe 46 leads through the wall of a compartment 47 and to a valve casing 48. From the casing 48 a pipe 49 leads to an automatic eX-. pansion valve 50, similar to the valve 42. Within the compartment 47 yis an expansion chamber 51, leading from the valve 50, having its coils within the compartment and leading outward through the wall of the compartment to the T 44, thus being in parallel with the expansion chamber 43. From the other outlet of the T 45 a feed pipe 52 leadsthrough the wall of a compartment 53 toa valve casing 54. From the casing 54 a pipe 55 -leads to an automatic eX- 115 pension valve 56, similar to the valve 42. lVithin the compartment 53 is an expansion chamber 57, leading from the valve 56, having its coils within the compartment and leading outward through the wall of the 120 compartment into that part of the expansion chamber 51 that has emerged from the compartment 47. Consequently so much of the expansion chambers 43, 51 and 57 as are within the compartments 41, 47, and 53, respectively, are in parallel with one another. For convenience of illustration the compartments 41, 47 and 53 are indicated as -being of the same size. So, also, the part of the' expansion chamber 51 that is within 130 the compartment 47 is longer than the part of the expansion chamber 43 that is within the compantment 4l and the part of the expansion chamber 57 that is within t-he compartment 53 is longer than the part of the expansion chamber 51 that is within the compartni-'t-nt 47. In practice the feed valve 38 is placed as near as practicable to the compartments 41, 47 and 53.

lVithin the casing 48, as shown in F ig. 6, is a valve seat 58 adapted to be closed from beneath by a conical valve 59, the stem of which extends upward through the valve seat. A flanged top 60 surrounds the upper part of the stem of the valve 59 and is screwed into a threaded opening in the upper part of the casing 48. A disc 61 is detachably secured to the upper end of the stem of the valve 59 and is adapted'tobreciprocate ashortdistance in a shallow chamber within the flange of the top 60 sufficiently to permit of the opening and closing of the valve 59. lVithin the top 60, at its axial center and below its shallow chamber, is a vertical chamber containing a. compression spring 62 that bears upward upon the dis'c 61 so as to tend to close the valve 59. A. diaphragm 63, preferably of vanadium steel, encloses the shallow chamber in the top 60, at its center rests upon the disc 61 and at its circ-uniference rests upon the rim of the flange of the top. A vertical tubular reservoir casing 64, positioned above and to the right of the casing 48, is supported by brackets 65, secured to the side wall of the compartment 47, so as to be spaced away from the wall. A head 66, enclosing the top of the casing 64, has a central vertical charging passage therethrough and a smaller transmitting passage extending upward and then to the left through an extension 0f the head. A narrow transmitting pipe 67, bent so as to form a right angle at the top, is secured at one end by a coupling -68 to the threaded left end of the extension of the head 66 and is secured at the lower end by a coupling 69 to the threaded upward exten-` sion of a flanged casing 70 that covers the diaphragm 63. Bolts 71 clamp the circumference of thevdiaphragm 63 between the rims of the top 60 and the casing 70. A flanged extension 72 is secured to the. lower end of the casing 64 and is closed on the under side by a thin metal diaphragm 73. A flanged casing 74 is secured by bolts 75 to the extension 72 so as to clamp the circumference of the diaphragm 73. Within the casing 74 is a foot 76, `having a threaded axial opening therethrough and having a flange secured to and bearing upward upon the center of the diaphragm 73. A regulating screw 77 is provided for the greater portion of its length with right hand threads 78. of a slight pitch, and at its upper end is of reduced diameter and is there provided of its threads 79, in the axial centralV open-.

ing in the foot 7 6, the head of the screw extending downward below the casing forthis purpose. A. flanged extension 80, secured to.the head 66 and having an axial passage in alineme-nt with the charging passage of the head, is enclosed o-n top by a thin metal relief diaphragm 81, adapted to rest on the extension, and is internally threaded above the diaphragm. A flanged stem 82 has its flange bearing downward upon the center of the diaphragm 81 and, is surrounded above its flange by a strong compression spring 83, that is stronger than the spring 62. A flanged clamping member 84 at its flange screws into the threaded part of the extension l8O so as to clamp the circumference of the diaphragmv 81, loosely surrounds the spring 83 and the flange of the stem 82, and is internally threaded on top. A head 85 screws into the threaded top of the member 84, surrounds the upper part of the spring 83, bears upon the top of the spring and has ay Vertical axial opening at the top through which the upper end of the stem 82 may reciprocate.

Before the diaphragm is clamped into position, some non-freezing liquid of a high coefficient of expansion, such as benzene or alcohol, which may be called the thermostatic liquid, isl introduced through the charging passage of the head 66 so as to fill the space enclosed thereby and by the parts 73, 72, 64, 67, 70 and 63. The parts 62-85 and the contained liquid constitute one form of' refrigerator thermostat 86. Within the compartment 53 is a thermostat 87 cooperating with a valve in the casing 54 similar to the valve 59.

lt is evident that the spring 62, bearing upon the disc 61, always tends to close the valve 59. When the thermostat is filled with liquid the capacity thereof is regulated by means ofthe screw 77. When the screw 77 is turned clockwise, the diaphragm 73 is drawn outward so as to increase the capacity of the containing walls and, the volume of the contained liquid remaining' constant, to increase the closing tendency of the spring 62; but' when the screw is turned counterclockwise, the diaphragm is forced inward so as to decrease the capacity of the containing wallsV and, the volume of the contained liquid remaining constant, to decrease the closing tendency of the spring. Suppose a refrigerating process is beginning in the compartment 47 with an adjustment by the screw 77 such that the valve 59 is fully open. Under such circumstances, the disc 61 is in its lll() position to the spring 83, has forced the stein 82 upward so that its top appears a greater or less 'distance above the head 85, thus serving as an indicator. As the refrigerating process progresses, the thermostatic liquid contracts, kvthe spring 83 forces the stem 82 land the diaphragm 81 to their lowest posi-1 tions, and finally the spring 62 more o-r less completely closes the valve 59. But if, as will be shown, the medium for refrigerating the compartment 47 has been passing the valve 59 during the refrigerating process' assumed, then, as the valve tends to close, the supply of refrigerating medium is so throttled that the tendency toward a cooling` down of the compartment is counteracted. An equilibrium is thus established and the compartment 47, so long as the flow of refrigerating medium continues, is kept at such temperature as has been determined by the` adjustment of the screw 77. If, for any cause, the iow of refrigerating medium past the valve 59 should cease, then the temperature of the compartment 47 would tend to rise to that of the outside atmosphere and the thermostatic liquid-would expand first so as to open the valve 59 to the limit permitted by the disc 61 and second so as to force the stem 82 upward, in opposition to thespring 83, thusy preventing a 'bursting of I the containing walls of the thermostat.

From the T. 44 a suction pipe 88 leads to the suction valve of a Acompressor 89. The

piping 3 discharges into the waterjacket of the compressor 89 and a waste pipe 90 discharges from the opposite upper part of the water packet. From a generator 91 a wire 92 leads to the upper one of a series of contacts 93 connected to one another by divisional or'psub-re'sistances. An arm 94 is pivoted near its left Vend, but is insulated from the pivot; it is p-ivoted near its center to a solenoid core 95, but is insulated therefrom; and at its right end it operates, upon the energization of the core, t0 make contact with the contacts 93, in ascending order, so as to cut outlthe resistances between the contacts successively. A dash pot device 96 is pivoted to the left end of the arm 94 and is operative to retard the upward movement of.

the right end of the arm. From the arm 94, near its pivot,a wire 97 leads to an electric motor 98, belt connected for driving the vcompressor 89, and Jfrom the motor a' wire the under side of the bracket 109, a little` to the left of the post 108, and is insulated from the bracket. From the post 110 a wire 111 leads to a contact block 112, secured to the under side of a bracket 113, but insulated therefrom. A contact block 114 is secured to the under side of the bracket 113, a little to the left of the block 112, and is insulated from the bracket.- From the block 114 a Wire 115' leads to a solenoid winding 116, adapted to energize the core 95. From the wind-f ing 116 a wire 117 leads to the point 100.

Secured at its lowerl end to the flathead Y.of the bello-ws 16 is a rod 118, adapted to re.-

guide 119 andy carrying above its insulated top a switch 120, ladapted to make contact with the contacts 112 and 114 and to connect them. A helical compression spring121 surrounds the rod 118, at its upper end bears upon the under side of the guide 119 and at its lower end bears upon the upper side of a nut 122, threaded upon the rod and secured in place by a 'lock nut 123. The spring 121 always tends to open the switch 120, but yields to an upward movement of the head. of the bellows 16 so as to permit of a closing of the switch.

A switch'arm V124 is pivoted to the lower end of the post 110; itn is adapted, as shown, when elevated to make a sliding contact within the split parts at the lower end of ciprocate in a the post 108; it has 'an insulated section just to the right of the post; it has a catch at its right end; and it has a depending lhandle near its right end. An angle bracket vertical part of the bracket 125;-it has a horizontal arm extending to the right and situated so that the right end is in the path of the left end of the lever 36 or '36, as the case may be, when ascending; it has a depending vertical arm with a catch on the left side at the lower end adapted to engage the right end of the arm 124 andv to hold it in contactwith the post 108, as shown; and it has projecting to the left above the arm a finger adapted to bear down upon thel arm when the lever 36r or 36,

be, bears upward againstr the horizontal arm. A flat spring 127, secured to the horizontal fpart of the bracketf125, bears upon the upper rightend of the horizontal arm of the lever 126 so as to tend to .rotate the lever clockwise. When the lever 126 is rotated counter-clockwise, in opposition to the spring'127,v the arm -124 is disengaged and, under force of gravity assisted by the linger of the arm, it drops out of-contact as the case may with the post 108, thus opening the switch, but is stopped from dropping too far by a pin 128. A

lin Fig. 1, as distinguished from Fig. 3, from the point 103 a wire 129 leads to the pivoted upper end of a thermostatic blade 130. The blade 130 is constructed, in the usual manner, of two flat strips, secured together, of materials having greatly unequal coeficients of expansion, so that, with a predetermined rise of temperature, its .free lower end will make Contact with an adjustable high temperature contact 131, and, with a predetermined fall of temperature, the lower end will make contact with -an adjustable low temperature contact 132. From the `contact 131 a wire 133 leads to the winding 21"; from the winding 21x a wire 134 leads to the winding 211'; and from the winding 21y a wire 135 leads to the Xed end of a spring circuit closer 136. From the con- 'tact 132 a Wire 137 leads to the winding 40"; from the winding 40x a wire 138 leads to the winding 40Y; and from the winding 40y a wire139 leads to the fixed end of a spring circuit-,closer 140.

rl`he parts 140-149, t0 be described, and the circuit closers 136 and 140 are to be understood to be a part of theconstruction common to Figs. 1 and 3, being more particularly disclosed in the latter figure. The lower end of the switch 106 is pivotally connected to a double end solenoid core 141. From a contact 142 a wire 143 leads to and from a solenoid winding 144, that surrounds the right end of the core 141, to a point From .a contact 146 a wire 147 leads to and from a. solenoid winding 148, that surrounds the left end of the core 141, to the point 145. From the point 145 a wire 149 leads to the wire 99. When the winding 148 is energized, it moves the core 141 to the left so that the conductor upper end of the switch 106 is out of contact with the contact 105, as shown, and the left end of the core forces the circuit closer 140 to the left and, away from the contact 146, as shown, the circuit closer having by reason ot its spring construction a tendency to return to the position of contact. But when the winding 144 is energized, it moves the core 141 to the right so that the conductor upper end of the switch 106 makes contact with the Contact 105 and the right end of the core forces the circuit closer 136 away from a closed position, as shown. into apposition away from the contact 142, this circuit breaker also having by reason of its' spring construction a tendency to return to the position ot contact. rlhe weight of the switch 106 and the 'core 141 is such and the friction of the core in sliding contact with the windings 144 and 148 is such that, after the winding 143 has been energized, the switch and the core stay in the position shown notwithstanding a slight tendency of the circuit closer 140 to push the core 141 to the right, and that, after the winding 144 has been energized, the switch and the core stay in the position to the right where the circuit closer 136 is away from the contact 142 notwithstanding a slight tendency of the circuit closer 136 to push the core to the left.

rllhe methodof operation of the parts disclosed in Figs. 1, 2, 4, 6 and so much of 3 as is common therewith and with Fig. 1 is as follows: Assume that the contacts 131 and 132 are so adjusted that on a rise of temperature to 36 degrees the blade 130 makes Contact with the contact 131 and on la fall of temperature to 33-degrees the blade makes contact with the Contact 132. Then, on a rise of temperature to 36 degrees, a current passes from the generator 91 through the parts 92, 101, 102, 103, 129, 130, 131, 133, 21x, 134, an, 135, 130, 112, 113, 144, 145, 149 and 99 back to the generator. The energization of the windings 21x and 21y opens the valves 37 and 38, which are so constructed as to remain open after such energization has ceased. And the energization of the winding 144 moves the core 141 to the'right so as to close the switch 106 upon the contact 105, to permit the circuit closer 140 to make contact with the contact 146 and to open the circuit closer 136. Consequently, when, on a subsequent cooling down of the compartment 41 below 36 degrees, the blade 130 leaves the contact 121, there will be no prolongation of contact and no wearing away of the parts.

V'Vith the opening of the valve 37, assuming a full supply of water is available, water flows through the parts 11, 12, 13, 14, 15, 3 and 90, thus taking up heat from the ammonia. in the tank 1 and trom the wat/er jacket ofthe compressor 89. But since the capacity of the pipe 13 is less than the capacity of the pipe 11 and the valve 37, the casing 12 and the bellows 16 ill up so that the pressure of the water, in opposition to Athe spring 121, closes the switch 120. Thereupon a current passes 'from the generator 91 through the narts 92, 101, 102,103, 104,105, 106, 107, 108, 124, 110, 111, 112,120, 111, 115, 110,117, 100 and 99 back to the generator. The energization of the winding 116l closes the arm 94 upon the contacts 93, begmnlng with the lowest, until eventually all the d1vis1onal resistances are cut out. lith the closlng of the lowest Contact 93. a current passes from the generator 91 through the wire 92, the contacts 93 and their divisional resistances, the arm 94 and t-he wire 97 to the motor 98 and thence through the wire 99 back to the generator; and, with a cutting out of all the divisional resistances. the full current 1s passing to the motor. Thereupon the motor 98 operates the compressor 89 so` as to draw expanded ammonia thence in pipe 88 -into from the pipe 88 and to force it through the pipe 4 into the tank 1. It is evident that the motor98 cannot start unless there is available a supply of water to fill the bellows 16.

With the opening of the valve 38, liquid ammonia from the tank 1 andthe pipe 5 passes through the valve and the T 39 and part through the pipe 40 to the valve 42. The valve 42, as is always the case with an automatic expansion valve, is set to correspond with the temperature to be vmaintained by the ammonia issuing and va.-

porizing therefrom. For a higher temperature the valve is set to permit a freer flow than for a 'lower temperature. The ammonia issuing from the valve 42 and Vaporizing in the expansion chamber 43 takes up heat from the compartment 41 and affects the blade 130. The expanding ammonia from the expansion chamber 43 passes through the T 44 and thence through the the compressor 89, as has been stated. But part of the` liquid ammonia passes from the T 39 through the T45, the pipe 46, the casing 48 and the pipe 49 to the valve 50. The ammonia issuingr from the valve 50, and vaporizing in the expansion chamber 51, takes up heat from the compartment 47 and affects the thermostat 86; and finally, in an expanded condition, it passes through the T 44 and the pipe 88 into the compressor 89. And part of the liquid ammonia from the T 45 passes through the pipe 52, the casing 54 and the pipe 55 to the valve 56. valve 56, and vaporizing in the expansion chamber 57, takes up heat from the'compartment 53.and affects the thermostat 87; and finally, in an expanded condition, it passes through the pipe 51, the T 44 and the pipe 88 into the compressor 89.

It is to be understood that the condenser is so proportionedr that, under normal conditions of operation, the` maximum flow of water through the piping thereof, even in the heat of summer,

will be capable of liquefying under a non-excessive head pressure the maximum weight of hot' ammonia gas forced into it per unit of time. Also in the cooler months of the year, or with a minimum weight ofy ammonia forced into the condenser per unit of time, a minimum How of condensing water, that is to say a lHow with the valve 17 in the position shown in Fig. 4, will suffice to prevent the head pressure from becoming excessive. Assume that the head pressure to be maintained is not to exceed say 160 pounds. Then, as the season advances and the water becomes warmer, or 'as a heavier duty is imposed upon theI apparatus, the minimum flow of condensing water 1s insuliclent to keep the head pressure below the limit assumed. `Under such circumstances, with a proper adjustment of the `from the generator 91 he ammonia issuing from the spring 27, as the head pressure rises to a few pounds less than 160 pounds, as indicated by the gage 2, the force exerted on lthe under side of the diaphragm 9 begins to lift it and to cause awider opening of the valve 17, as has been explained. Thereupon more water flows. through the condenser piping and the head pressure tends to fall and to permit the spring 27 to exert the maximum throttling 'efech An equilibrium is thus established so as normally to maintain the predetermined head pressure. Obviously this tendency of the head pressure to rise may be so greatas to result in an opening of the valve 17 to the maximum. The primary adjustment of the thrust of the spring 27 is made Aby means of t-he bolt 28 and the nut 29 and the secondary adjustment, so as to maintain the particular head pressure desired, is made by turning the bolt 21 and the locknut 22 up or down. After the primary adjustment has been made, the cap 30 and the casing 24 would properly be sealed, as has been indicated, and then any operator of the apparatus would be free to make such secondary adjustment as might be desired.

`When, in the course of operation, the temperature in the compartment 41 falls to.33 degrees, the blade 130 makes contact with the contact 132. Thereupon a current passes through the parts 92, 101, 102, 103, 129, 130, 132, 137, 40", 138, 40Y, 139, 140, 146, 147 148, 145, 149 and 99 back to the generator. The energization of the windings 40x and '40V closes the valves 37 and 38, ywhich are so constructed. And the energization of theiwinding 148 moves the core 141 to the left, as shown, so as to open the switch 106, to permit the circuit closer 136 to make contact with the contact 142 and to open the circuit closer' 140. Consequently, when, on the ensuing rise of temperature in the compartment 41.y the blade 130 leaves the contact 132, there will be no prolongation of contact and nowearing away of the parts.

With the opening'of .the switch 106, the current through the winding 116 ceases, the core 95 isde-energized, the arm 94 drops out of contact with the contacts 93, the current through ,the motor 98 ceases and the motor and the compressor 89 begin to slow down, running, however,.for a short time `the supply in the reservoir is exhausted.

Such supply, therefore, prevents an excessive head pressure while` the compressor 89 isslowing down. With the closingof the valve 38 the flow of liquid ammonia therethe water level in the bellows 16 so as to open the switch 120 and to interrupt the current through the Winding 116. Such interruption has the same effect as does the opening of the switch 106 in stopping the compressor 89 and in affording a supply of condensing water while the compressor is running down. But, upon a resumption ot the water supply and a filling up'of the bellows 16, the switch 1420 closes and the operation of the apparatus is resumed in substantially the way that has been explained in reference to the starting of the normal cycle. And sometimes it will happen, while the compressor 89 is running with a maximum How of condensing water, that even such a flow does not prevent the head pressure from exceeding the predetermined limit. Such a condition may arise in case the condenser is too small or is ill designed, or in oase the condenser piping is allowed to become foul, or in case non-condensable gases become Apresent in the upper part of the tank 1. The head pressure might become high enough, from some such cause, as to open the valve 10 and thus to release the aminonia charge, or, in case such a valve were not provided, to cause an explosion of the plant. But the emergency device, consisting of thefparts 108--110 and 124--128 prevents any such consequence. For, after the condenser pressure has exceeded 160 pounds and the lever 36 has been entirely lifted from the bolt 21, the ascending lever, say at 20 or 30 pounds higher pressure, such being the adjustment of the 'spring 27, trips the lever 126 and opens the switch arm 124, so as to interrupt the current through the winding 116. Such interruption has the same effect as does the opening of the switch 106 or the opening of the switch 120 in stopping the compressor 89; but herethe flow of condensing water continues indefinitely, with the tendency of reducing the excessive head pressure. With the particular emergency device shownjwhich is essentially the same as that disclosed in Fig. 7 as modified by Fig. 17 of my aforesaid application Ser. No. 146,147, rather than that disclosed in Figs. 15 and 16 thereof, after a drop of the head pressure to normal, a manual act isnnecessary to close the arm 124, as by moving its handle clockwise. Such a manual act is intended to occur after an investigation and avremooval .of the cause of the abnormal pressure. By

the employment of the emergency device, it results that the valve 10 will open only in case of a tire involving the plant.

JV ith the compartments 41, 47 and 53 of the same size and with the retrigerating capacity of the expansion chamber 57 greater than that of the expansion chamber 51 and that of the latter greater than that of the expansion chamber 43, all other material conditions being substantially the same, assume that it is desired to maintain some certain temperature in the compartments 47 and 53. It may be here stated that the automatic expansion valves'42h50 and 56 are simply automatic reducing valves, so constructed as to regulate the flow of ammonia therefrom, and thereby to maintain thel pressure in the piping leading there` from at a predetermined limit and thus to predetermine the temperature within the piping; and that the advantage of such valves over the ordinary hand valves is that frequent manual adjustments to secure t`ese results'are rendered unnecessary. The temperatures in the compartments 41, 47 and 53 tend to approximate the temperatures produced by the vaporization of the ammonia in the expansion chambers 43, 51 and 57, respectively. Such tendencies, if unchecked. would result in too low temperatures. ln the case of the compartment 41, the tendency toward too'low a temperature is counteracted by the stopping of the compressor 89 when the blade 130 makes contact with the contact 132. But under the conditions stated, before the blade 130 could make contact with the 'contact 132, the temperatures in the compartments 47 and 53 would fall too low. Accordingly the thermoatats 86 and 87 are adjusted so as to prevent such results, the screw 77 being used for that purpose, and to this end they operateV as will now be explained. As the thermostatic fluid in the thermostat 86 'begins to contract, the valve 59 tends to close and thus to throttle the flow of liquid ammonia to the valve 50. At rst such a' throttling, by lessening the supply, may decrease the` pressure of the vaporizing ammonia issuing :trom the valve 50 and thus may actually increase the refrigerating eect in the compartment 47. But it is evident that, as the throttling continues, after a brief time the supply is so diminished that, even although the temperature irithe expansion chamber 51 tends to become very cold, there is so little ammonia to vaporize therein that such tendency is counteracted by the rising tendency of the temperature in the compartment 47 An equilibrium is thus established so that the temperature in the compartment 47 is kept to its predetermined low limit, until the blade 130 makes contact with the Contact 132 andthe entire process of refrigeration is suspended. ln the compartment 53-the only diii'erence in operation is that the .thermostatv87, under they conditions assumed, begins to exert its throttling effect before the thermostat 86 begins to act.

the specific heat of the contents of the com-,

partments, the frequency with which the contents are renewed, and the like. The general rule therefore is this: For secondary compartments, such as the compart-y ments 47 and 53, in parallel with the master compartment 41, the refrigerating capacities of the secondary expansion chambers in each, such as the expansion chambers'51 and 57, should be such that they will be capable of cooling down the secondary` compartments to their predetermined low limits, while the apparatus is in active operation, before the master'expansion chamber 43 can cool down the master compartment to its predetermined low limit.

With thev stationary parts positioned as shown in Fig. 4, for a thermostatic control of the' starting and stopping of the compressor 89, the ow and the non-How of water into thepipe 11, by some such means 37 as is herein disclosed, is necessary. On the other hand, the valve38 is only of-slight utility. For, when the compressor 89 is standing idle, while the temperature in the compartment 41 is rising from 33 to 36 degrecs, there is always a tendency of the ammonia from the high pressure side to leak into the expansion chambers, also spoken of as the low pressure side, and thereby to cause a rise ofl pressure therein. Such a leakage may be backward through the dis charge and suction valves ofthe compressor 89 or it may be forward through the valves 42, 50 and 56, if any such valve becomes worn. Such a condition of high pressure puts a strain vupon that part of the apparatus that was designed to withstand only a low pressure.. Furthermore, when, on a rise of temperature in the compartment 41 from 33 to 36 degrees, the compressor89 again starts, at first it is occupied, with a waste of power, in pumping down the expansion chambers 43, 51 and 57 so as to produce low enough pressures to permit. of vaporization therein. And it" is apparent that, even with the valve 38 very close to the valves 40, 50

vand 56 and preventing leakage from the pipe 5 therethrough, the valve 38 is incapable of preventing a back flow. of ammonia through the discharge and suction valves of the compressor 89. Y

1 Secondly, considering the-construction --of Figs. 2, 3, 5, 6, a7 and so much of Fig. 1 as is applicable thereto: In Fig. 7 a hand switch 150 is interposed in the wire192, by means of which the apparatus may be placed within or withdrawn rom the thermostatic controlthereof. The parts 93, 94, 95, 96 and asshown in Fig. 3, to a series of contacts 116 constitute one form of self starting rheostat, commonly termed a self starter, any such rheostat -being adapted to close the cir-r cuitof a motor. but tending to open the circuit. I am not to be understood as being limited to any particular form of such rheostat. lThe wire 97 leads to a point 151 and l the wire 99 leads from the point 100. From the point 151 a wire 152, as a series winding, leads, with the proper number of turns, around cores 153 and thence leads to, an armature 154. From the armature 154 a wire .155 leads through a point 156 to the point 100. From the point 151 a wire 157 leads,

8. 158, which for convenience of illustration are shown to be eightA in number. Counting from the left, between the first four of the contacts 158' are divisional resistances 159 and between the fourth and the subsequent four are other divisional, resistances 160. A hand switch 161 is so connected to two of the contacts 158 that ywhen closed, as shown, it short circuits such of the resistances 159 as are between the second and fourth contacts. But vwhen the switch 161 is open, a current must pass through all the resistances 159. It is to be understood that the switch 161 may be so connected to the first and 'fourth contacts 158 as to short circuit, when closed, all the resistances 159 or it may be connected so as to short circuit certain of the resistances in any other combination. A switch 162 at its upper end is shown in contact with the eighth contact 158 and is adapted to make contact with the fourth Contact, after having cut out all the resistances 160. If so desired, the contacts 158 may be so positioned that the switch 162 will make successive contacts with any other two of the eight. From the switch 162 a wire 163 leads to the upper end of contacts 164, arranged in descending order and connected with one another by divisional resistances 165. The contacts"164 are so positioned that the conductor 36h, when the lever 36a ascends, will make conitact with the contacts successively and will cut out the resistances 165 successively. Fromv the lower one of the contacts 164 a 115 wire 166 leads to a point 167, shown in Fig. 7. From the point 167 two wires 168 and 169, as field windings, with the proper number of turns, in parallel with each other, lead around the cores 153, each wire leading 120 around half of` the cores, to ar point 170. From the point 170 a wire 171 leads to the point 156. The parts 152, 153, 154,155, 167, 168, 169 and 170 thus constitute part of a cumulative compound motor 172, that is to 125 be understood to be connected for driving the compressor 89. y

Together with the switch 162, the parts 173, 174, 1,75, 176,177, 178, 179. 189 and 181 are identical inconstruction and opera- 130 tion with the part-s 106, 136, 142, 143, 144, 141, 140, 146, 147 Vand 148, respectively, except that the wires 175 and 180 lead to the wire 149.

vA master refrigerator thermostat 182, shown in Fig. 3 and more in detail in Fig. 5, has as the basis of its construction an ordinary Bourdon tube pressure gage, such as the gage 2, adapted to measure the pressures either of ammonia or of sulphur dioxide, as may be preferred. A short tube 183 is to be understood to be connected with the fixed end of the Bourdon tube and to contain a little liquid ammonia or sulphur dioxide, as the case may be, so that, upon a rise of temperature and Vapor pressure in the Bourdon tube, by means of the familiar mechanism employed in such gages, the free end of the Bourdo-n tube will rotate clockwise a switch 184, similar to the pointer on such gages, and, upon a fall of such temperat-ure and pressure, the free end will rotate the switch counter-clockwise. Thie shaft 185 therefor and is positioned in front of an insulating face plate 186. From the point 103 the wire 129, properly insulated, leads to the ixed end of the switch 184. The plate 186 has, arranged in a circle near its circumference, screw holes 187, a short distance apart from one another and extending part way through the plate. A long arc shaped high temperature starting contact 188 is detachably secured to the plate 186, on the right hand side, by screws' 189, screwing into certain of the holes 187, A comparatively short arc shaped piece 190 is detachably secured to the plate 186, on the left, by screws 191, screwing similarly into certain of the holes 187 at the top it consists of a narrow low speed Contact 192; and, for most of its length, it consists of a low temperature stopping contact 193, insulated from the contact 192. rllhe free end of the switch 184 is shown in a middle position betw'een the contacts 192 and 188. Assume that the tube 183 contains a small quantity of liquid ammonia. Let it bel assumed that the switch 184, as will be explained, is to start the compressor 89 at a temperature of 37 degrees and to stop it at a temperature of 33 degrees. For a temperature of 37 degrees the corresponding ammonia vapor pressure is 54 pounds gage;

' andfor a temperature of 33 degrees, 48.6

pounds gage. rlhe vcontact 188 is vtherefore positioned, byJmeans of the screws 189,

so that the switch 184 will make a sliding contact with the left end of the contact at an ammonia vapor pressure of 54 pounds. And the piece 190 is positioned, by means of the screws 191, so that the switch 184 will make a sliding contact with the right end r'of the contact 193 at an ammonia vapor pressure of 48.6 pounds. The contact 192 is so narrow and the insulation between it and the contact 193 is so narrow that, upon a movement of the switch 184 counter-clockwise, it will rst make a sliding contact with the Contact 192 at a pressure of 50 pounds, corresponding to a temperature of 34 degrees. The circular length of the contact 188 is so great that the switch 184 will be in contact therewith at any temperature between 37 degrees and the maximum atmospheric temperature, thus causing the thermostat 182 to be operative when it is desired initially to start `the compressor 89 with a temperature inside the compartment 41 as high as the outside temperature. Similarly the circular length of the contact 193 is so great that the switch 184 will be in contact therewith between33 degrees and the lowest temperature that can be produced in the compartment 41, thus causing the thermostat 182 to be always operative to stop the compressor 89 even although some other part of the apparatus might fail to act in effecting such stopping.

From the contact 188 a wire 194 leads to the pivoted end of a hand switch 195.` The wire 133 leads from a Contact 196 to the winding 21", as before. From the winding 215 the wire 135 leads to a contact 197. The switch 195 is shown in contact with the contact 197, but it may be turned into contact with the contact 196. From th'e contact 197 a wire 198 leads to a point 199. From the point 199 one wire 200 leads to the fixed end ofl the circuit closer 136 and another wire 201 leads to the fixed end of the circuit closer 178. From the contact 192 a wire 202 leads to the fixed end of the circuit closer 173. From the Contact 193 a wire 203 leads to the pivoted end of a hand switch 204. The wire 137 leads from a contact 205 to the winding 40", as before. From the winding 40y the wire 139 leads to a' contact 206.` The switch 204`is shown in contact with the contact 206, but it may be turned into contact with the contact 205. From the contact- 206 a wire 20'( leads to the fixed end'of the circuit closer 140. I am \not limited to the particular kind of thermostat 182 above described. Any thermostat having a starting contact, a stopping contact and an intermediate low speed contact will accomplish my purpose.

The method of operation of the parts disclosed in Figs. 2, 3, 5, 6 and 7 and so much of Fig. 1 as is applicable thereto is as follows: It is assumed that the thermostat 182 replaces the parts 130, 131 and 132 in the compartment 41 and that the Valves 37 and 38 have been operated 'so as now to be open. For it will appear that the Valves 37 and 38 are not essential to the present construction, the possibility of their omission being one of the advantages of the present construction. On a rise of temperature inv'the llO i I ...N

compartment 41 toy 37 degrees, a current passes from the generator 91 through )the parts 101, 102, 103, 129, 184, 188, 194., 195,

197,198, 199, 200, 136, 142, 143, 144 145 and The energizay '140 to make contact with the contact 146 and to open the circuit closer 136. Consequently, When, on a subsequent cooling down of the compartment 41 below 37 degrees, the switch 184 leaves the contact 188, there will be no prolongation of contact and no burning away of the/parts. Y

There being a free inflow through the pipe 11, assuming that there is 1o accidental failure of the water supply,'the switch 120 is in a closed position; and Jthis is so whether the valve 17 is open, as previously considered, or is closed, as shown.` With the closing 0f the switch 106 there is the same closing of the armv 94 upon the contacts 93, with a cutting out 'of the divisional resistances, that has been described already. Thereupon a current passes from the generator 91 through the wire 92, the arm 94, the wire 97 and the point 151 and thence 'in part through the winding 152, the armature 154, the wire 155, the points 156 and 100 and the wire y99 back to the generator. But from the point 151 a part of the current passesthrough the wire 1,57, some of the contacts 158, part of the resistances 159, the switch 161, the resistances 160, the' switch 162, the wire 163, the contacts 164, the resistances 165, the wire 166, the point 167, the windings 168 and '169, the point 170, the wire 171, the point 156 and the wire 99 back to the generator. The motor 172 and the compressor 89 start the process vof refrigeration i'n the compartments 41, 47 and 53, as before.

Whether the valve 17 is open or shut when the motor 172 starts depends upon the atmospheric temperature outside of the tank 1. To maintain a head pressure of 160 pounds, it is necessary that the valve 17 should begin to open say at 150 pounds pressure. 9 A temperature of 84 degrees out side of the tank 1 and hence also within the tank corresponds to a pressure of 150 pounds for the ammonia vaportherein. Consequently, if a head pressure of 160 pounds is to be maintained, whenever the outside.

temperature is at or above84 degrees, there will be a How of condensing water whether the compressor 89 is running or is standing idle. But, whether the valve 17 is open. or

'J shut, as hot gas is forced into the tank 1, the

pressure pn the under side of the, diaphragm 9 forces it upward So ras to cause a further opening of the valve 17 and the maintaining of an equilibrium, as before. 1f, in thel warmer months 0f thel year, itis desired to prevent a waste of the while the compressor 89 is standing idle, the switches 195 and 204 may be turned into contact with the contacts 196 and 205, `respectively, s0 that the valve 37 (and the' valve 38, if retained) will operate as before.

When, in the course of operation, the temperature in the compartment 41 falls to 34 degrees, the switch 1'84 makes contact with the Contact 192. Thereupon a current passesy through the parts fromv` the generator 91 101, 102, 108, 129, 184, 192, 202, 178, 171, 175, 176 and 149 back to the generator. The energization of the winding 176 moves the core 177 to the right so as to move the switch f 162 from contact with the eighth contact 158 into contact with the fourth contact to cut out the resistances 160, to permit the circuit closer-.178 to make contact with the contact 179 and to open the circuit closer 173. In consequence of the opening of the circuit closer 173, it willhappen that, when the switch 184 leaves, -in either direction,

the contact 192,r there will be no prolongation of contact and no burnin away of thel parts. The cutting out of t e resistances 160 strengthens the field and causes an increase of the counter electromotive force of the motor 172 so that itsspeed and the speedof the compressor 89 decrease. Consequently les's ammonia per unit of time4 is circulated through the expansion chambers condensing water, f

43, 51 and 53 .and the temperature in the compartment 41 may tend to rise. Under such circumstances, either` one of two results will happen. First: There may be a rise of temperature in the compartment 41 so as to cause the switch 184 to make contact with the contact 188. Thereupon, as at the starting, al current from the generator 91 passes to the point 199; but, the circuit closer 136 being open, fromthe point 199, the current 17 8, 179, 180 and 149 back to the generator. The energization of the winding 181 moves the lcore 177 to the left so as to move the switch 162 back into contact with the eighth contact 158, to throw in the resistances 160, to permit the circuit closer 173 to make contact with the contact '174 and to open the circuit closer 17 8 lthus restoring theparts to their original position. 'The throwin in of the' resistances 160 weakens ,theA fiel and causes a decrease of the counter electromotive -force of the motor 172 so that its passes through the parts 201,

speed and the speed of thecompressor 89 ini crease., Consequently more ammonia per unit of time is circulated through the expansion chambers 43, 51 and 53 and the temperature in the compartment -41"wi11 fall to 34 degrees, with the same eifect as before. This changing from full speed to low speed and the reverse, according to the temperature requirements of thecompartment 41, is the f ideal condition. For it is apparent that with a change ,ofthe motor 172-from low speed t0 full speed there can be n0 such waste of power as there is when a dead motor is started up. The extent to which t-he resistances in line with the field windings 168 and 169 can be cut out may be varied by opening or closing the switch 161 and by changing its connections with certain other of the co-ntacts 158, as has been indicated. These variations may be made with. the progress 0f the seasons or as the duty imposed on the apparatus increases or diminishes in consequence of its particular employment. But, second, it may happen that, notwithstanding the cutting out of the resistances 160, the temperature in the compartment 41 may continue to fall, reaching 33 degrees. Thereupon, as the switch 184 makes contact with the contact 193, a current passes from the generator 91 through the parts 101, 102, 103, 129, 184, 193. 20a. 204, 200, 207, 140, 140. 14e, 147 and 149 back to the generator. r1`he energization of the winding 148 moves the core 141 to the left so asto 'open the switch 106, to permit the circuit closer 136 to make contact with the contact 142 and to open the circuit closer 140. Consequently, when, on the ensuing rise of temperature in the compartment 41, the switch 184 leaves the contact 193, there will be no prolongation of contact' and no burning away of the parts.

With the opening of the switch 106. the motor 172 and the compressor 89 slow down and stop, as in the first construction. Unless there is a failure of the supply of condensing water, the switch 120 is continuously closed. llfithe head pressure is above 150 pounds, the valve 17 remains open until there is a sufficient drop of pressure to close it. And, as before, while the mo-tor 172 and the compressor 89 are slowing down there is a supply of condensing water sufficient to prevent an excessive head pressure. But, if, as was possible, the switches 195 and 204 had been turned into contact with the contacts 196 and 205, respectively. the valve 37 (and the valve 38. if retained) close when the switch 184 makes contact with the contact 193 and the inflow of condensing water into the casing 12 is shut off.

On a rise of temperature in the compartment 41 to 34 degrees, the switch 184 makes contact with the contact 192, but normallythere will be no actuation of the switch 162 e because the circuit closer 173 vis open; but,

if, lby reason of any accidental displacement of the parts (as was assumed to be the case in describing the starting), the circuit closer 173 should happen to be closed, as shown, the only effect would be to cut out the resistances 160, to close the circuit closer 178 and to open the circuity closer 17 3, or, in other words` to position the parts as they would be positioned in the absence of the accident.

On a further rise of temperature in the compartment 41 to 37 degrees, the switch 106 is closed and the motor 172 and the compressor 89 start up, as before. Furthermore fand this is the normal condition--a part of the current from the generator 91 through the point 199 passes through the parts 201. 178, 179, 180, 181 and 149 back to the generator. so that the energization of the winding 181 throws inthe resistances 160, causes the closing of the circuit closer 173 and opens the circuit closer 178, as before. Consequently. when the starting rheostat has acted so as to transmit the full current to the motor 172` the compressor 89 is operating at its full capacity.

Sometimes it will happen, while the compressor is running, that there will be an accidental failure of the water supply entering the pipe 11. Under such circumstances there is a drop of the water pressure in the bellows 16 so as to open the switch 120 and to interrupt the current through the winding 1'16. thus stopping the compressor 89, as before. Upon a resumption of the supply and a sufficient rise of water in the bellows 16, the switch 120 closes and the control of the apparatus is restored to the thermostat 182. In this construction. therefore, as distinguished from the first construction, the switch 120 acts merely as a safety device.

ln case the maximum flow of condensing water is insufficient in preventing the head pressure from exceeding the predetermined normal limit, say of 160 pounds, the lever 36a ultimately may trip the lever 126 and stop the compressor 89. as has been described in reference to the lever 36 in the first construction. But here, before the lever 126 can be tripped, the conductor 36", as the lever 365L ascends. makes contact with the contacts 164 successively and cuts out the resistances 165 successively, rI `he effect is to strengthen the field and to cause an increase of the counter electromotive force of the motor 172 so that its speed and the speed of the compressor 89 decrease in the same manner a's when the resistances 160 are cut out. The slowing down of the compressor 89 causes less ammonia to be forced into the tank 1 so that the head pressure may cease to rise and the lever may not be tripped at all. And if the head pressure should drop back to normal` the action in reference to the contacts 164 and the resistances 165 reverses. so that the compressor 89 resumes its full duty. Accordingly. both under the control of the temperature in the compartment 41 and under the control of excessive condenser pres- ,.sure. the motor 172 operates as a variable speed motor and the compressor 89 operates as a variablespeed compressor. There has not been, however any attempt herein to illustrate a particular kind of motor adapted to the maximum reduction of speed by Fig. 8 in connection with certain parts of the second form of construction: The defectA of the means for varying the speed of the motor 172 in the second form of constructlon'is that when the resis-tances 160 are cut out, so'

as to slow down the motor, the resistances 165 remain 1n series except 1n the very rare occurrence of an abnormal head pressure beyond the control of they maximum flow of condenslng water. Therefore, under ordinary circumstances, the extent to which y'the motor 172 can be slowed. down is much restricted. .This difficulty is remedied `in the third form of construction. For convenience of illustration the contacts 164 arefive in number and will be. counted from the top. The resistances 165 are omitted. vA contact 208 isbelow the fourth Contact 158.` The wire 163 is disconnected from its former co-nnections and no7 connects the eighth contact 158 and the contact 208. The fifth, sixth,

y seventh andeighth contacts 158 are so high as to be out of theV ath of the switch 162. The sole function of) the switch 162, when the winding 176 is energized, is toconnect the fourth contact 158 and the `contact20'8; and, when the winding 181 is energized, it disconnects these contacts. A wire 209 connects the fourth contact 164 and the seventh contact 158; a wire 210 connects the rthird contact 164 and the sixth contact 158; a wire 211 connects the second contact 164 and the fifth contact 158; a'wire 212 connects the first contact 164 and the fourth contact 158; and

.a'wire 213 connects the fifth Contact 164 and the contact 208.

Consequently, when the switch 162 outof connection with the contact 208, a current may pass through the resistances 160, the contacts 158, the wire 163, the contact 208, the wire 213, the fth contact 164 and the parts in series with these named parts. But, whenA the switch 162 connects the fourth contact 158 and the contact 208, the current will pass through the fourth contact 158, the switch 162, the'contact 208 andthrough the parts in series therewith, thus cutting out the resistances'160. And when the ascending conductor 36" ta'cts 164 successively, beginning with the fifth, on making contact with thefourth 4contact 164, a current passes through'the wire 209 and one quarter of the\resistances 160' are cut out, on making contact with the third contact 16,4 a current passes through the Wire 210 and one half of the resistances are cut out, on making contact with the second contact 164 a' current passes through' the wire 211 and three quarter of the resistances are makes contact with the concut out and on making contact with the first contact 164 a current passes through the wire 21,2 and all 'the resistances are out out. 'And this; result happens'A quite independently of the position of the switch 162. By this preferred means of cutting out the resistances Q 160, the speed of the motor 172 'can be very greatly reduced'when either the thermosta't'182 or the controller operates in rela-l tion thereto. By the low speed control of the motor 172 there is greatly lessened the waste of power existing in the first construction in consequence of ther starting up of the motor after each of its frequent stoppings and of the associated pumping down ofthe expansion chambers. And. the motor 172 startsso rarely from a dead stop that the valve 38 may be omitted.

Fourthly, considering the construction of Fig. 9 in connection With certain parts of the prior construction The pipe 11 leads into the vlower left side of a reservoir casing214 and the pipe 13 leads `from the lower right sideA of the casing. A shaft 215 extends through the front wall of the casing 214; .it has secured to its back end within the casing an arm ending in a float 216; and it has secured to its front end `o'utsideof the casing a lever 217, extending in a direction opposite tothat of the interior arm. A cord 218 at one end is secured to the free end of the lever 217;. itpassesvupward over pulleys 219 and 220; it. has at its depending other end a weight 221; and it has above the weight actuating buttons 222 and 223. Ay pivoted bell crank lever 224 has an opening through the end of a lower armyextending to the right, through which opening passes the part of the cord `218 th'at is between the buttons 222 and 223; and it :has a weight ball 225 at thegend of the other arm, extending upward. A stop 226-prevents -the ball225 from falling too far to the right and a stop 227 prevents the ball from falling too far to the left. A conductor section of the upper arm of the lever 224 is -insulated at the top from the part that may rest upon the contacts 226 and 227 and also from the part near the pivot. When .the ball 225 and the adjacent partof the arm is inv contact with contacts 228 and 229, so as to connecty them. The wire 111 leads to the conductor 22,8 and the wire 115 leads` from the conductor 229. 1

This fourth construction may be used as a substitute for the'parts 12, 16, 112, 113, 114, 118, 119, 120, 121, 122 and 123 already considered. On a rise of the water level in the casing 214, the float 216 rises and depresses the lever 217 so as to pull the cord 218 over the pulleys 219 and 220 untll the button 223 actuates the lever 224 into a position Where' the ball 225 is to the left of lits vertical center. The ball 225 then drops, until the stop" 227 prevents any further movement, so that the conductor part of the upper arm of the lever 224 connects the contacts 228 and 229, thus having the same effect as does the closing of the swvitch 120. On a subsequent drop of the water levelin the casing 214, the float 216 falls and the' Finally considering the construct-ion 'of' Fig. 10: Here, by ay transposition of the parts, the valve 5() is placed between the pipes 46 and 49 and the casing 48 and the thermostat 86 are placed between the pipe 49 and the expansionchamber 51. Asimilar transposition may be made of the parts 54 and 87 and the part 56. Neither such arrangement is preferred over the prior.I construction.

While the parts disclosed are adapted for use in connection one with another as has been described, yet many of the elements may be used in other connections. For example, the means for slowing down the motor 172 in case of excessive condenser pressure and for speeding it up to normal upon a drop 0f pressure to normal may be used. separately not merely in connection with a manually controlled refrigerating machine but also in connection with any kind of electrically operated forcing means for forcing fluid into a container. So, also, the thermostatically controlled means for slowing down and speeding up the motor 172 may be used apart from the condensery pressure controlled means for so doing. So, also, the parallel feed system for one or a plurality of compartments associated with a master compartment 41 may be use-d separately both with a manually started land stopped compression refrigerating machine and also with any kind of absorption refrigerating machine. 'Ihe first form of construction is similar in principle to the form of construction disclosed in my aforesaid application Ser. No. 126,019, as modifiedl by the construction of Fig. 8 thereof, with the addition that by the present construction an additional valve, such as the Valve 38,

can be thermostatically controlled.

1. In combination, a refrigerating apparatus including a condenser, an'eXpansion chamber and a compressor in circuit, an

'electric motor for driving the compressor,

and a thermostat at a high temperature limit operating the motor at full speed, at a medium temperature limit operating it at ing a condenser,

low speed and at a low tempera-ture limit stopping it.

2. In combination, a refrigerating apparatus including a condenser, an expansion chamber and a compressor in circuit, electric means for driving the compressor, a starting contact, a low speed contact, a stopping contact and a thermostat at a high temperature limit closing a circuit through the starting contact to operate the compressor at full speed, at a medium temperature limit closing a circuit through the low speed contact to operate the compressor at low speed and at a low temperature limit closing a circuit through the stopping contact t-o stop the compressor.

3. In combination, a refrigerating apparatus including a condenser, an expansion chamber and a compressor in circuit, electric means for driving the compressor, a starting contact, a low speed contact, a stopping contact, a co-nductor for engaging any of the contacts, a thermostat at a. high temperature limit closing a circuit through the conductor and the starting contact' to operate the compress-or at full speed, at a medium temperature limit closing a circuit through the conductor and the low speed contact to operate the compressor at low speed and at a low temperature limit closing a circuit through the conductor and the stopping contact to stop the compressor, and means breaking the current through the conductor andeach contact upon the engagement thereof.

4. In a refrigerating system includan expansion. chamber leading therefrom and a compressor leading from the chamber into the condenser, and temperaturev controlled means at a high temperature limit operat- ,.condenser, an expansion chamber leading therefrom and a compressorv leading from the' chamber into the condenser, an electric motor for driving the compressor and having a shunt winding and resistances in series therewith, and temperature controlled means at a high temperature'limit operating the motor at'full speed, at a medium temperature limitv cutting out certain of said resista-moes and at a low temperature limit stopping theV motor.

6. In a refrigerating system, a compartment, an expansion chamber therein, a condenser leading into the chamber, forcing means for drawing expanded refrigerant from the chamber and forcing it into the condenser, and means controlled by the temperature of the compartment and varying the rate of operation of the forcing .means according to the refrigeration requirements of the compartment but stop-ping said means at a low temperature limit.

T. In combination, a condenser, forcing means for forcing Huid into the condenser, controlling means for operating the forcing means either at full capacity or at part capacity, and means controlled by the head pressure to operate said means at part capacity in case such. pressure becomes excessive. S. In combination, a condenser, forcing means for forcing Huid into the condenser, controlling means for operating the forcing means either at full capacity orat part ca.- pacity` and means controlled by the head pressure to operate said means at part capacf ity in case such pressure becomes excessive and to sto-p said means on a further rise of pressure.

' means for operating the compressor at full or fall of such pressure.

speed or at 10W speed, and means controlled by the head pressure to operate the compressor at low speed or at full speed with a rise 10. Invcombination, a condenser, a compressor leading into the condenser, controlling means for operating the compressor at full speed or at low speed, and means controlled by the head pressure to operate the compressor at low speed or at full speed with a rise or fall of such' pressure and to stop case lof a high excessive l2. In combination, a condenser, electrically operated forcing means for forcing Huid into the condenser, and means controlled by the head pressure to vary the rate of operation of the forcing means according to the Variations of such pressure and stopping said means in case of a high excessive pressure.

13, In combination, a condenser, acompressor leading into the condenser, fan elec-- tric motor for driving the compressor, and means controlled by the head pressure to run the motor at low speed or at full speed with a rise or fall of such pressure.

14. In combination, a condenser, aY compressor lea-ding into the condenser, an electric motor for driving the compressor, and means controlled by the head pressure to run the motor at low speed or at full speed With a rise o-r fall of such pressure and to stop the motor in case of a high excessive pres- JNO. W. PIPER, WILLIAM REINER.

. Sure. 

